Memory devices are typically provided as internal, semiconductor, integrated circuits in computers or other electronic devices. There are many different types of memory including random-access memory (RAM), read only memory (ROM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), flash memory, phase change random access memory (PCRAM), spin torque transfer random access memory (STTRAM), resistive random access memory (RRAM), magnetoresistive random access memory (MRAM; also referred to as magnetic random access memory), conductive-bridging random access memory (CBRAIVI), among others.
Some types of memory devices can be non-volatile memory and can be used for a wide range of electronic applications in need of high memory densities, high reliability, and low power consumption. Non-volatile memory may be used in a personal computer, a portable memory stick, a solid state drive (SSD), a personal digital assistant (PDA), a digital camera, a cellular telephone, a smartphone, a tablet, a portable music player, e.g., MP3 player, a movie player, and other electronic devices, among others. Program code and system data, such as a basic input/output system (BIOS), are typically stored in non-volatile memory devices.
Many memory devices, such as RRAM, PCRAM, MRAM, STTRAM and CBRAM, for example, can include arrays of memory cells organized in a two-terminal cross-point architecture, for instance. Arrays of memory cells in a two-terminal cross-point architecture can include electrodes that have planar surfaces between the memory cell material. For filamentary-type memory device, e.g., RRAM and/or CBRAM, the location of the active region of the memory cell between planar surfaces of the electrodes can be variable because the planar surfaces of the electrodes provide a substantially uniform electric field across the memory cell material.